Now, the banks have a problem on their hands. "The Cypriot cabinet has declared Tuesday a bank holiday, for fear of capital flight, and this may even be stretched to Wednesday, as depositors are certain to withdraw huge sums from the Cypriot banks after the haircut imposed," reports Greek newspaper Kathimerini.

Many market observers are expressing concerns that the decision could have a ripple effect throughout Europe come Monday when markets open. After all, if European leaders have decided to violate the unspoken rule of bank bailouts – that deposits are sacrosanct – what's to say it can't happen in a bigger eurozone country, like Spain?

In a Sunday morning note to clients, Morgan Stanley economist Joachim Fels wrote, "I view this as a worrying precedent with potentially systemic consequences if depositors in other periphery countries fear a similar treatment in the future."

"This will probably go down as an ill-thought-out rescue plan with consequences for peripheral Europe," says Galy. "It breaks a cardinal rule — namely, public trust on which money relies."

The decision, therefore, has everyone scratching their heads. Why would European leaders play with that public trust in bank deposits?

In other words, German politicians are up for re-election in September, and bailouts of other countries with German taxpayer funds don't help their cause much. So, Cyprus had to be made to share in the burden somehow — hence the haircut on deposits.

"Conditionality is here to stay!" wrote SocGen economist Michala Marcussen in a reaction to the deal. "Indeed, there appears to be no change in the economic policy model of austerity and structural reform that has characterised the euro crisis to date."

The Italian elections demonstrated that voters fed up with that austerity could ultimately break the confidence instilled in European markets since ECB President Mario Draghi gave his famous "whatever it takes to save the euro" speech in July.

The Cyprus deal may finally be a good illustration of the risks markets face from the influence German voters as well — the ones ostensibly coming at the austerity debate from the exact opposite perspective.

"It could be the trigger that our colleagues were expecting," says SocGen strategist Sebastien Galy.